Frozen food containers are often marketed in cartons constructed from unitary blanks comprising waterproof paperboard having flaps that are folded and sealed to insure product freshness. In response to the growing demand for convenience foods and the popularity and ready availability of microwave ovens for quickly heating such foods, containers have been developed that may be taken directly from the freezer and heated in a microwave (or conventional) oven. Most such containers are folded from a paperboard blank that includes gusseted corners so that the bottom of containers thus constructed forms a leakproof tray. After the container is filled with the product through the open top, the top is closed and sealed along the sides.
The instructions for heating some food products require that the consumer open the container by pulling back a tear-open flap either prior to or during the heating process to expose the product and/or to permit water, butter or seasoning to be added. The tear-open flap may be partially reclosed by inserting a tab on the end of the flap into a slot provided on a side of the container. Due to the design of prior art containers of this type, the tear-open flap cannot be fully reclosed; a wedge-shaped gap remains between the top and the access flap when the tab is fully inserted into the slot. Steam may escape through this gap when the product is heated. Although certain products may require that steam be allowed to escape while being heated, for the majority of food products, it is desirable to more tightly reclose the flap so that steam trapped within the container more quickly cooks the product.
When frozen food containers are displayed to the consumer for sale in a supermarket, it is a common practice to present a graphic representation of the product enclosed in the container imprinted on the top surface and sides. Heating instructions are normally relegated to the bottom surface of the container. The tear open panel is on the top surface of such containers, and thus the container is placed in an oven to heat its contents with the instructions facing downwardly. Prior to opening the package or initiating the heating process, the consumer may freely turn the container over to read the instructions without any adverse consequences. However, once the product is heated so that it is partially thawed and/or the top of the package is opened, reference to the instructions printed on the bottom may require holding the container high overhead, risking spillage of the contents. Since multiple microwave oven power levels and time levels are often required to cook food products, the need to refer to instructions during the heating process may frequently arise.
It may seem relatively trivial to correct the problem associated with placement of heating instructions on the bottom of the container, but this is not the case with prior art packaging. Conventional microwavable/ovenable containers of necessity must have a leakproof portion on the bottom during the heating process. Flaps on the top portion overlap the outside of the bottom portion on at least three sides. It is not practical to merely interchange the surfaces on which the graphics and instructions are normally imprinted on such a container, since the raw edges of the flaps would be exposed if the container were thus inverted, reducing product marketability. Marketing considerations thus dictate the need to imprint the graphics on the top surface and the instructions on the bottom surface of conventional containers.
In consideration of the problems represented by prior art food packaging containers as described above, it is a primary object of this invention to provide a top filled container useful for heating the product enclosed therein in a microwave or conventional oven and having an access flap which may be tightly reclosed after being opened by a consumer.
Further objects of this invention are to provide a top filled container that may be tightly reclosed for storage of an unused portion of the product, preventing it from drying out; to provide such a container which when reclosed, is easier to handle with less chance of spilling its contents; to provide such a container in which food may be cooked more rapidly than in conventional containers which tend to vent excessive amounts of steam from the product; and to provide a container with more conventiently displayed cooking instructions and with graphics covering a smooth top surface and side panels.
These and other objects of the invention will be apparent to those of ordinary skill in the art to which this invention pertains, by reference to the attached drawings and the disclosure of the preferred embodiment that follows hereinbelow.